本文關(guān)鍵詞： 鎂合金 限制性模壓 力學(xué)性能 金相組織 劇烈塑性變形　出處：《山東大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：作為目前最輕的金屬結(jié)構(gòu)材料,鎂及其合金自上世紀(jì)90年代以來(lái)便迅猛發(fā)展,在有色金屬產(chǎn)業(yè)中占據(jù)非常重要的地位。由于比強(qiáng)度、比剛度高,具有良好的減震性能、鑄造以及加工性能等優(yōu)點(diǎn),其在國(guó)防、交通以及電子電器設(shè)備等行業(yè)都具有廣闊的應(yīng)用前景以及市場(chǎng)需求。但由于鎂獨(dú)特的密排六方結(jié)構(gòu),常溫下塑性較差,限制了其在塑性成形領(lǐng)域的應(yīng)用。限制性模壓(CGP)變形技術(shù)作為一種自上而下制備超細(xì)晶材料的方法,通過累積應(yīng)變將原有晶粒破碎來(lái)細(xì)化金屬材料從而提高金屬的加工塑性和超塑性。它不改變材料的外觀形狀及尺寸,通過變形過程中引入大的應(yīng)變量使板材晶粒得到細(xì)化,從而使材料機(jī)械性能得到提高,該技術(shù)在低碳鋼、純鋁、純銅等金屬上得到應(yīng)用并取得良好效果。本文通過數(shù)值模擬與工藝實(shí)驗(yàn)相結(jié)合的方法對(duì)AZ31鎂合金板材的限制性模壓變形進(jìn)行研究,詳細(xì)分析了 CGP變形過程對(duì)板材力學(xué)性能和微觀組織的影響規(guī)律,討論了 CGP變形對(duì)鎂合金板材晶粒細(xì)化的變形機(jī)理,揭示了后續(xù)退火工藝過程中板材力學(xué)性能與微觀組織的變化情況。論文主要研究?jī)?nèi)容如下:利用有限元模擬技術(shù)基于DEFORM軟件建立鎂合金CGP工藝模型并進(jìn)行變形工藝仿真分析。通過鎂合金CGP變形過程中的載荷、網(wǎng)格變形、材料流動(dòng)以及應(yīng)變場(chǎng)分布的變化規(guī)律,分析了鎂合金CGP變形過程中模具與板材的變化情況,研究了變形過程中板材的變形機(jī)理與應(yīng)變累積分布規(guī)律。為實(shí)驗(yàn)?zāi)＞叩脑O(shè)計(jì)與工藝實(shí)驗(yàn)的進(jìn)行建立了理論依據(jù)。進(jìn)行AZ31鎂合金板材限制性模壓實(shí)驗(yàn),通過調(diào)整不同的變形溫度、變形速率、模壓方式與模壓次數(shù)分析不同CGP變形參數(shù)對(duì)鎂合金板材的影響規(guī)律,討論鎂合金CGP變形的最優(yōu)條件。通過對(duì)CGP變形板材的拉伸測(cè)試,分析CGP變形對(duì)鎂合金板材在沿模壓方向與垂直模壓方向上力學(xué)性能的影響特點(diǎn)。通過金相顯微組織觀察分析,揭示CGP變形對(duì)板材晶粒組織的影響變化規(guī)律。進(jìn)行CGP退火工藝實(shí)驗(yàn)分析,通過對(duì)退火溫度與退火時(shí)間的調(diào)整,分析CGP板材在不同退火工藝參數(shù)下力學(xué)性能與晶粒組織的變化情況,討論CGP變形后的AZ31鎂合金板材最優(yōu)退火條件。進(jìn)行退火板材的熱拉伸實(shí)驗(yàn)與金相組織觀察,研究鎂合金CGP板材在退火過程中宏觀性能與微觀組織的變化機(jī)理。
[Abstract]:As the lightest metal structural material at present, magnesium and its alloys have developed rapidly since -10s, and occupy a very important position in the nonferrous metal industry. It has broad application prospects and market demand in the fields of national defense, transportation, electronic and electrical equipment and so on. However, due to the unique dense hexagonal structure of magnesium, the plasticity is poor at room temperature. Limiting its application in the field of plastic forming. As a top-down method for the preparation of ultrafine grained materials, limited moulding CGP-based deformation technology, The original grain is broken by cumulative strain to refine the metal material and improve the working plasticity and superplasticity of the metal. It does not change the appearance and size of the material, and the grain size of the plate is refined by introducing large strain variables in the process of deformation. So that the mechanical properties of the materials are improved, the technology in low carbon steel, pure aluminum, Pure copper and other metals have been applied and good results have been obtained. In this paper, the restrictive moulding deformation of AZ31 magnesium alloy sheet was studied by means of numerical simulation and process experiment. The effect of CGP deformation process on mechanical properties and microstructure of magnesium alloy sheet was analyzed in detail. The deformation mechanism of CGP deformation on grain refinement of magnesium alloy sheet was discussed. The changes of mechanical properties and microstructure of magnesium alloy during subsequent annealing process are revealed. The main contents of this paper are as follows: the finite element simulation technology is used to establish the CGP process model of magnesium alloy based on DEFORM software and the deformation process is carried out. Through the load of magnesium alloy CGP deformation process, The variation law of mesh deformation, material flow and strain field distribution is analyzed. The change of die and plate during CGP deformation of magnesium alloy is analyzed. The deformation mechanism and strain accumulation distribution of AZ31 magnesium alloy sheet during deformation were studied. The theoretical basis for the design of experimental die and process experiment was established. The limiting molding experiment of AZ31 magnesium alloy sheet was carried out, and different deformation temperatures were adjusted. The influence of different CGP deformation parameters on magnesium alloy sheet was analyzed, and the optimum conditions of CGP deformation of magnesium alloy were discussed. The tensile test of CGP deformed sheet was carried out. The influence of CGP deformation on the mechanical properties of magnesium alloy sheet in the direction of molding and vertical molding was analyzed. The effect of CGP deformation on the grain structure of sheet metal was revealed. The experimental analysis of CGP annealing process was carried out, and the annealing temperature and time were adjusted. The change of mechanical properties and grain structure of CGP sheet under different annealing process parameters is analyzed. The optimal annealing conditions of AZ31 magnesium alloy sheet after CGP deformation are discussed. The thermal tensile test and metallographic observation of annealed sheet are carried out. The change mechanism of macroscopic properties and microstructure of magnesium alloy CGP sheet during annealing was studied.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG146.22;TG166.4

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 王輝;劉滿平;唐愷;李毅超;韋江濤;姜奎;江家威;;大塑性變形制備超細(xì)晶/納米晶Al-Mg鋁合金的研究進(jìn)展[J];材料導(dǎo)報(bào);2016年15期

2 段永強(qiáng);;金屬材料發(fā)展的新趨勢(shì)及其影響[J];橡塑技術(shù)與裝備;2015年24期

3 張念先;Megumi Kawasaki;黃毅;Terence G.Langdon;;晶粒尺寸對(duì)大塑性變形的兩相合金超塑性的影響（英文）[J];材料與冶金學(xué)報(bào);2015年04期

4 彭開萍;張秀妹;林雪慧;;等效應(yīng)變對(duì)Cu-38Zn合金交叉模壓形變后組織和性能的影響[J];材料熱處理學(xué)報(bào);2014年02期

5 吳永泉;楊開懷;陳文哲;;5052鋁合金在CGP過程中的變形模型[J];熱加工工藝;2012年19期

6 孫朝陽(yáng);欒京東;劉賡;李瑞;張清東;;AZ31鎂合金熱變形流動(dòng)應(yīng)力預(yù)測(cè)模型[J];金屬學(xué)報(bào);2012年07期

7 陳啟東;溫華兵;;基于Deform-2D的薄板沖裁有限元分析[J];機(jī)械設(shè)計(jì)與制造;2012年05期

8 汪程鵬;李付國(guó);陸紅亞;王磊;喬慧娟;;劇烈塑性變形制備微納米材料的變形細(xì)化機(jī)理[J];金屬熱處理;2012年02期

9 楊開懷;陳文哲;;變形方式對(duì)模壓變形5052鋁合金影響的有限元模擬與試驗(yàn)研究[J];材料研究學(xué)報(bào);2011年06期

10 楊開懷;彭開萍;陳文哲;;限制模壓變形1060純鋁的組織演化與晶粒細(xì)化[J];中國(guó)有色金屬學(xué)報(bào);2011年12期

相關(guān)碩士學(xué)位論文 前4條

1 張博;AZ31鎂合金板材在不同限制模壓條件下組織和性能研究[D];太原理工大學(xué);2016年

2 李紹龍;AZ31鎂合金板材的限制性模壓工藝研究[D];山東大學(xué);2015年

3 梁萍;純鋁/純銅板材的限制性模壓工藝研究[D];山東大學(xué);2013年

4 李乃樸;擠壓軋制復(fù)合工藝制備AZ61鎂合金板材的研究[D];大連理工大學(xué);2012年

，

本文編號(hào)：1548263